Controlling H+3 Formation From Ethane Using Shaped Ultrafast Laser Pulses

Abstract

An adaptive learning algorithm coupled with 3D momentum-based feedback is used to identify intense laser pulse shapes that control (Formula presented.) formation from ethane. Specifically, we controlled the ratio of D2H+ to (Formula presented.) produced from the D3C-CH3 isotopologue of ethane, which selects between trihydrogen cations formed from atoms on one or both sides of ethane. We are able to modify the D2H+: (Formula presented.) ratio by a factor of up to three. In addition, two-dimensional scans of linear chirp and third-order dispersion are conducted for a few fourth-order dispersion values while the D2H+ and (Formula presented.) production rates are monitored. The optimized pulse is observed to influence the yield, kinetic energy release, and angular distribution of the D2H+ ions while the (Formula presented.) ion dynamics remain relatively stable. We subsequently conducted COLTRIMS experiments on C2D6 to complement the velocity map imaging data obtained during the control experiments and measured the branching ratio of two-body double ionization. Two-body (Formula presented.) + (Formula presented.) is the dominant final channel containing (Formula presented.) ions, although the three-body D + (Formula presented.) + (Formula presented.) final state is also observed.